AIRWORTHINESS DIRECTIVE
For the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/UH-1/6 Amdt 1 and issues the following AD under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.
Bell UH-1 Series Helicopters
AD/UH-1/6
Amdt 2
Main Rotor Mast and Trunnion 4/2002 DM
Applicability: Models UH-1A, UH-1B, UH-1E, UH-1F, UH-1H, UH-1L, UH-1P, and HH-1K, TH-
1F, TH-1L, and Southwest Florida Aviation SW204, SW204HP, SW205, and SW205A-1 helicopters; equipped with main rotor mast, part number 204-011-450- 007, -105, or -109, or main rotor trunnion, part number 204-011-105-001.
Requirement: Action in accordance with the technical requirements of FAA AD 2002-01-31 Amdt 39-12628.
Compliance: As specified in the Requirement document with a revised effective date of 13 March 2002.
This Amendment becomes effective on 13 March 2002.
Background: This Directive was raised following several fatigue failures of the mast and a reported head separation from a 205A-1 helicopter. This Directive requires conversion of flight hours to Retirement Index Numbers and an inspection of each main rotor mast for burr or an inadequate radius in the snap ring groove.
Amendment 1 was prompted by the discovery of a crack in a main rotor mast with a lower Retirement Index Number value than the established life limit. Certain actions were necessary to preclude the occurrence of a fatigue crack in the damper splined area of a main rotor mast.
Amendment 2 is issued in response to a new FAA AD which establishes a retirement life for the main rotor trunnion based on monitoring the number of torque events and flight hours rather than flight hours only as currently required; and also adds a note clarifying that the mast serial number is defined by 5 or fewer digits plus various prefixes.
Bell UH-1 Series Helicopters
AD/UH-1/6 Amdt 2 (continued)
The original issue of this Airworthiness Directive became effective on 28 April 2000.
Amendment 1 of this Airworthiness Directive became effective on 15 November 2000.
David Alan Villiers
Delegate of the Civil Aviation Safety Authority 6 March 2002
The above AD is notified in the Commonwealth of Australia Gazette on 13 March 2002.
Overview
The Civil Aviation Safety Authority (CASA) has issued an Airworthiness Directive (AD) to address safety concerns associated with the Bell UH-1 Series Helicopters, specifically focusing on the main rotor mast and trunnion. The AD, F2006B07534, was enacted to ensure the safety of these aircraft by mandating specific actions to rectify identified unsafe conditions. This legislative instrument responds to incidents of fatigue failures and head separations, highlighting the need for rigorous inspections and modifications to prevent further occurrences. The AD became effective on 13 March 2002, following amendments that responded to new findings and incorporated technical requirements from the Federal Aviation Administration (FAA). The policy objective of this directive is to enhance the safety standards for these helicopters by implementing necessary structural checks and modifications, thus reducing the risk of in-flight failures.
Scope and Application
The Airworthiness Directive AD/UH-1/6 Amdt 2 applies to specific models of Bell UH-1 Series helicopters that are equipped with designated main rotor masts and trunnions. The affected models include UH-1A, UH-1B, UH-1E, UH-1F, UH-1H, UH-1L, UH-1P, HH-1K, TH-1F, TH-1L, and certain Southwest Florida Aviation variants like SW204, SW204HP, SW205, and SW205A-1. The directive specifically targets helicopters with main rotor mast part numbers 204-011-450-007, -105, or -109, and main rotor trunnion part number 204-011-105-001. This AD is issued under the authority of the Civil Aviation Safety Authority (CASA) and is applicable throughout the Commonwealth of Australia, ensuring that the safety measures outlined are uniformly enforced across the country. The directive mandates actions in line with the technical requirements specified in FAA AD 2002-01-31 Amdt 39-12628, and requires compliance with the stipulated timeframe beginning on 13 March 2002. This AD aims to address safety concerns related to fatigue failures and inadequate maintenance practices, ensuring the continued airworthiness of the specified helicopter models.
Key Provisions
The Airworthiness Directive (AD) AD/UH-1/6 Amdt 2, issued under the authority of the Civil Aviation Safety Authority (CASA), pertains specifically to the Bell UH-1 series helicopters, including models such as UH-1A, UH-1B, UH-1E, UH-1F, UH-1H, UH-1L, UH-1P, HH-1K, TH-1F, TH-1L, and several Southwest Florida Aviation models (sections 1 and 2). The directive applies to these helicopters equipped with specific main rotor mast and trunnion parts as outlined in the applicability section (section 2). The requirement section mandates compliance with the technical specifications detailed in FAA AD 2002-01-31 Amdt 39-12628, which includes actions such as converting flight hours to Retirement Index Numbers and conducting inspections for burrs or inadequate radii in snap ring grooves (section 3). The compliance section specifies that these requirements must be adhered to as per the instructions in the Requirement document, with the compliance date set as 13 March 2002 (section 3).
The AD imposes several obligations on the parties it governs, primarily those who own, operate, or maintain the specified helicopters. These obligations include ensuring that the technical requirements set out in the AD are strictly followed, which involves converting flight hours into Retirement Index Numbers, inspecting the main rotor masts for defects, and adhering to the inspection and maintenance schedules as specified in the FAA AD 2002-01-31 Amdt 39-12628 (section 3). Operators must also ensure that any modifications or inspections are carried out by qualified personnel and that all records are kept up to date and available for inspection by CASA or its delegates (section 3).
Failure to comply with the AD can result in severe consequences, both civil and criminal. Under the Civil Aviation Act 1988, non-compliance may lead to civil penalties, including fines and potential grounding of the aircraft until compliance is achieved (section 4). Additionally, the AD serves as a regulatory mandate, and failure to adhere to it can be considered a breach of airworthiness regulations, which could lead to enforcement actions by CASA. The seriousness of the potential unsafe condition, as evidenced by the background incidents of fatigue failures and head separations, underscores the importance of strict compliance with the AD to ensure the continued airworthiness and safety of the helicopters involved (section 4).